6Ghz, 1:6 CML Fanout Buffer with 2:1 Mux Input and Internal

Micrel, Inc.
Precision Edge®
SY58034U
®
6GHz, 1:6 CML FANOUT BUFFER
WITH 2:1 MUX INPUT AND
INTERNAL I/O TERMINATION
Precision Edge
SY58034U
FEATURES
Provides six ultra-low skew copies of the selected
input
2:1 MUX input included for clock switchover
applications
Guaranteed AC performance over temperature and
voltage:
• Clock frequency range: DC to > 6GHz
• <290ps IN-to-OUT tpd
• <60ps tr / tf times
• <20ps skew (output-to-output)
Unique input isolation design minimizes crosstalk
Ultra low-jitter design:
• 60fs RMS phase jitter
• <0.7psRMS crosstalk-induced jitter
Low supply voltage operation: 2.5V and 3.3V
Unique input termination and VT pin accepts DCcoupled and AC-coupled inputs (CML, PECL, LVDS)
Internal 50Ω output source termination
Precision Edge®
DESCRIPTION
The SY58034U is a 2.5V/3.3V precision, high-speed 1:6
fanout buffer capable of handling clocks up to 6GHz. A
differential 2:1 MUX input is included for redundant clock
switchover applications.
The differential input includes Micrel’s unique, 3-pin input
termination architecture that allows the device to interface
to any differential signal (AC- or DC-coupled) as small as
100mV without any level shifting or termination resistor
networks in the signal path. The outputs are 50ý source
terminated CML, with extremely fast rise/fall times
guaranteed to be less than 60ps.
The SY58034U operates from a 2.5V ±5% supply or a
3.3V ±10% supply and is guaranteed over the full industrial
temperature range of –40°C to +85°C. For applications that
require LVPECL outputs, consider the SY58035U or
SY58036U Multiplexers. The SY58034U is part of Micrel’s
high-speed, Precision Edge® product line.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
400mV CML output swing
–40°C to +85°C temperature range
Available in 32-pin (5mm x 5mm) QFN package
FUNCTIONAL BLOCK DIAGRAM
APPLICATIONS
Redundant clock distribution
All SONET/SDH clock distribution
All Fibre Channel distribution
All Gigabit Ethernet clock distribution
1:6 Fanout
Q0
/Q0
2:1 MUX
IN0
Q1
50Ω
VT0
50Ω
/Q1
0
Q2
/IN0
VREF-AC0
MUX
/Q2
S
Q3
IN1
50Ω
VT1
50Ω
1
/Q3
/IN1
Q4
VREF-AC1
/Q4
SEL
(TTL/CMOS)
Q5
/Q5
Precision Edge is a registered trademark of Micrel, Inc.
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Rev.: E
Amendment: /0
Issue Date: August 2007
Precision Edge®
SY58034U
Micrel, Inc.
PACKAGE/ORDERING INFORMATION
GND
SEL
VCC
Q0
/Q0
Q1
/Q1
VCC
Ordering Information(1)
32 31 30 29 28 27 26 25
IN0
VT0
VREF-AC0
/IN0
IN1
VT1
VREF-AC1
/IN1
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
Package
Marking
Lead
Finish
SY58034UMG
QFN-32
Industrial
SY58034U with
NiPdAu
Pb-free bar-line indicator Pb-Free
SY58034UMGTR(2)
QFN-32
Industrial
SY58034U with
NiPdAu
Pb-free bar-line indicator Pb-Free
Notes:
1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC electricals only.
2. Tape and Reel.
GND
NC
VCC
/Q5
Q5
/Q4
Q4
VCC
9 10 11 12 13 14 15 16
GND
VCC
Q2
/Q2
Q3
/Q3
VCC
GND
Package Operating
Type
Range
Part Number
32-Pin QFN
PIN DESCRIPTION
Pin Number
Pin Name
Pin Function
1, 4
5, 8
IN0, /IN0
IN1, /IN1
Differential Input: These input pairs are the differential signal inputs to the device. These
inputs accept AC- or DC-coupled signals as small as 100mV. Each pin of a pair internally
terminates to a VT pin through 50ý. Note that these inputs will default to an indeterminate
state if left open. Please refer to the “Input Interface Applications” section for more details.
2, 6
VT0, VT1
Input Termination Center-Tap: Each side of the differential input pair terminates to a VT
pin. The VT0 and VT1 pins provide a center-tap to a termination network for maximum
interface flexibility. See “Input Interface Applications” section for more details.
31
SEL
This single-ended TTL/CMOS-compatible input selects the inputs to the multiplexer. Note
that this input is internally connected to a 25ký pull-up resistor and will default to a logic
HIGH state if left open. The MUX select switchover function is asynchronous.
10
NC
No connect.
11, 16, 18,
23, 25, 30
VCC
29, 28
27, 26
22, 21
20, 19
15, 14
13, 12
Q0, /Q0,
Q1, /Q1,
Q2, /Q2,
Q3, /Q3,
Q4, /Q4,
Q5, /Q5
9, 17, 24, 32
GND,
Exposed Pad
3, 7
VREF-AC0,
VREF-AC1
Positive Power Supply: Bypass with 0.1µF™™ 0.01µF low ESR capacitors and place as
close to the VCC pins as possible.
Differential Outputs: These CML output pairs are low skew output copies of the selected
input. The output stage is optimized to deliver a 400mV swing (single-ended) into 50ý.
Each output includes a 50ý source-termination resistor, thus minimizing any return
reflections. Unused output pins may be left floating. Please refer to the “Truth Table”
for details.
Ground. Ground pin and exposed pad must be connected to the same ground plane.
Reference Voltage: These output biases to VCC–1.2V. It is used for AC-coupling inputs
(IN, /IN). Connect VREF-AC directly to the VT pin. Bypass with 0.01µF low ESR capacitor to
VCC. See “Input Interface Applications” section. Maximum sink/source current is ±1.5mA.
Due to the limited capability, the VREF-AC pin is only intended to drive its respective VT
pin.
TRUTH TABLE
SEL
0
IN0 Input Selected
1
IN1 Input Selected
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Precision Edge®
SY58034U
Micrel, Inc.
Absolute Maximum Ratings(1)
Operating Ratings(2)
Power Supply Voltage (VCC ) ...................... –0.5V to +4.0V
Input Voltage (VIN) .......................................... –0.5V to VCC
CML Output Voltage (VOUT) ........... VCC–1.0V to VCC+0.5V
Termination Current
Source or sink current on VT pin ........................ ±100mA
Input Current
Source or sink current on IN, /IN pin .................... ±50mA
Source or sink current on VREF-AC pin ................. ±2mA
Lead Temperature (soldering, 20 sec.) ..................... 260°C
Storage Temperature Range (TS ) ........... –65°C to +150°C
Power Supply Voltage (VCC) ............... +2.375V to +2.625V
............................................................. +3.0V to +3.6V
Ambient Temperature Range (TA) .............. –40°C to +85°C
Package Thermal Resistance(3)
QFN (θJA)
Still-Air ............................................................. 35°C/W
QFN (ψJB)
Junction-to-Board ............................................ 16°C/W
DC ELECTRICAL CHARACTERISTICS(4)
TA= –40°C to 85°C, unless otherwise stated.
Symbol
Parameter
VCC
Power Supply Voltage
Condition
Min
Typ
Max
Units
2.375
2.5
2.625
V
3.0
3.3
3.6
V
245
320
mA
ICC
Power Supply Current
No load, max. VCC
RDIFF_IN
Differential Input Resistance
|IN–/IN|
90
100
110
ý
RIN
Input Resistance (IN-to-VT)
45
50
55
ý
VIH
Input HIGH Voltage (IN, /IN)
VCC–1.6
VCC
V
VIL
Input LOW Voltage (IN, /IN)
0
VIH–0.1
V
VIN
Input Voltage Swing (IN, /IN)
See Figure 1a.
0.1
1.7
V
VDIFF_IN
Differential Input Voltage Swing
|IN, /IN|
See Figure 1b.
0.2
VT IN
IN to VT (IN, /IN)
VREF-AC
Reference Voltage
Note 5
V
1.28
VCC–1.3 VCC–1.2 VCC–1.1
V
V
Notes:
1. Permanent device damage may occur if the measurements in the “Absolute Maximum Ratings” section are exceeded. This is a stress rating only
and functional operation is not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute
maximum ratings conditions for extended periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Thermal performance assumes exposed pad is soldered (or equivalent) to the device’s most negative potential on the PCB. ΨJB and θJA are
determined for a 4-layer board in a still air, unless otherwise stated.
4. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
5. VIH (min) not lower than 1.2V.
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Precision Edge®
SY58034U
Micrel, Inc.
CML OUTPUT DC ELECTRICAL CHARACTERISTICS(6)
VCC = 2.5V ±5% or 3.3V ±10%; TA= -40°C to 85°C; RL = 100ý across each output pair or equivalent, unless otherwise stated.
Symbol
Parameter
Condition
Min
Typ
Max
VOH
Output HIGH Voltage
VOUT
Output Voltage Swing
RL = 50ý to VCC
See Figure 1a.
VDIFF_OUT
Differential Output Voltage Swing
See Figure 1b.
ROUT
Output Source Impedance
VCC–0.020
VCC
Units
V
325
400
mV
650
800
mV
40
50
60
ý
Min
Typ
Max
Units
LVTTL/CMOS DC ELECTRICAL CHARACTERISTICS(6)
VCC = 2.5V ±5% or 3.3V ±10%; TA= -40°C to 85°C, unless otherwise stated.
Symbol
Parameter
Condition
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
IIH
Input HIGH Current
–125
IIL
Input LOW Current
–300
2.0
Note:
6. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
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V
0.8
V
40
μA
μA
Precision Edge®
SY58034U
Micrel, Inc.
AC ELECTRICAL CHARACTERISTICS(7)
VCC = 2.5V ±5% or 3.3V ±10%; TA= –40°C to 85°C, RL= 100ý across each output pair, or equivalent, unless otherwise stated.
Symbol
Parameter
Condition
fMAX
Maximum Operating Frequency
Clock VOUT ž 200mV
tpd
∆tpd Tempco
Min
Typ
6
7.5
Differential Propagation Delay
(IN0 or IN1-to-Q)
140
220
290
ps
(SEL-to-Q)
100
200
400
ps
Differential Propagation Delay
Temperature Coefficient
tSKEW
tJITTER
Units
GHz
65
fs/°C
Output-to-Output
Note 8
20
ps
Part-to-Part
Note 9
100
ps
RMS Phase Jitter
Output = 622MHz
Integration range: 12kHz - 20MHz
Adjacent Channel
Crosstalk-Induced Jitter
tr, tf
Max
Output Rise/Fall Time
60
Note 10
Full swing, 20% to 80%
20
fs
0.7
psRMS
60
ps
Notes:
7. High frequency AC electricals are guaranteed by design and characterization.
8. Output-to-output skew is measured between outputs under identical transitions.
9. Part-to-part skew is defined for two parts with identical power supply voltages at the same temperature and with no skew of the edges at the
respective inputs.
10. Crosstalk is measured at the output while applying two similar clock frequencies that are asynchronous with respect to each other at the inputs.
SINGLE-ENDED AND DIFFERENTIAL SWINGS
VDIFF_IN,
VDIFF_OUT 800mV (Typ.)
VIN,
VOUT 400mV (Typ.)
Figure 1a. Single-Ended Voltage Swing
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Figure 1b. Differential Voltage Swing
5
Precision Edge®
SY58034U
Micrel, Inc.
TIMING DIAGRAMS
IN
/IN
tpd
Q
/Q
Input-to-Q tpd
SEL
VCC/2
VCC/2
tpd
tpd
Q
/Q
SEL-to-Q tpd
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Precision Edge®
SY58034U
Micrel, Inc.
TYPICAL OPERATING CHARACTERISTICS
VCC = 2.5V, GND = 0, VIN = 100mV, RL = 100ý across the output; TA = 25°C, unless otherwise stated.
450
400
350
300
250
200
150
100
50
0
0
224
PROPAGATION DELAY (ps)
OUTPUT SWING (mV)
500
Output Swing
vs. Frequency
2000 4000 6000 8000 10000
FREQUENCY (MHz)
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Propagation Delay
vs. Temperature
222
220
218
216
214
-40 -20
0
20
40
60
TEMPERATURE (C)
7
80 100
Precision Edge®
SY58034U
Micrel, Inc.
FUNCTIONAL CHARACTERISTICS
VCC = 2.5V, GND = 0, VIN = 400mV, RL = 100ý across the output; TA = 25°C, unless otherwise stated.
Output Swing
(100mV/div.)
2.5GHz Output
Output Swing
(100mV/div.)
200MHz Output
5GHz Output
7GHz Output
Output Swing
(100mV/div.)
TIME (50ps/div.)
Output Swing
(100mV/div.)
TIME (600ps/div.)
TIME (30ps/div.)
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TIME (20ps/div.)
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Precision Edge®
SY58034U
Micrel, Inc.
INPUT AND OUTPUT STAGES
VCC
VCC
50Ω
IN
50Ω
/Q
Q
50Ω
VT
GND
50Ω
/IN
GND
Figure 2a. Simplified Differential Input Stage
Figure 2b. Simplified CML Output Stage
INPUT INTERFACE APPLICATIONS
VCC
VCC
VCC
IN
LVPECL
IN
CML
SY58034U
CML
NC
VREF-AC
GND
NC
VT
VCC
Option: May connect VT to VCC.
Figure 3a. CML
Interface (DC-Coupled)
GND
/IN
SY58034U
GND
/IN
IN
/IN
SY58034U
0.01μF
Figure 3b. CML
Interface (AC-Coupled)
VCC
LVPECL
Rpd
IN
SY58034U
Rpd
LVDS
/IN
GND
VCC
GND
SY58034U
VREF-AC
0.01μF
VT
For 3.3V, Rpd = 100Ω
For 2.5V, Rpd = 50Ω
Figure 3d. LVPECL
Interface (AC-Coupled)
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GND
VT
NC
VREF-AC
NC
VT
Figure 3e. LVDS Interface
9
Rpd
For 3.3V, Rpd = 50Ω.
For 3.5V, Rpd = 19Ω.
VT
/IN
VREF-AC
VCC
0.01μF
VREF-AC
VCC
IN
NC
Figure 3c. LVPECL
Interface (DC-Coupled)
Precision Edge®
SY58034U
Micrel, Inc.
OUTPUT INTERFACE APPLICATIONS
VCC
VCC
50Ω
50Ω
50Ω
50Ω
/Q
/Q
50Ω
100Ω
Q
Q
DC bias point per application
50Ω
16mA
16mA
GND
GND
Figure 5. CML AC-Coupled
Termination
Figure 4. CML DC-Coupled
Termination
RELATED MICREL PRODUCTS AND SUPPORT DOCUMENTATION
Part Number
Function
Data Sheet Link
SY58035U
4.5GHz, 1:6 LVPECL Fanout Buffer with 2:1
MUX Input and Internal Termination
http://www.micrel.com/product-info/products/sy58035u.shtml
SY58036U
6GHz, 1:6 400mV LVPECL Fanout Buffer with 2:1
MUX Input and Internal Termination
http://www.micrel.com/product-info/products/sy58036u.shtml
HBW Solutions
New Products and Applications
www.micrel.com/product-info/products/solutions.shtml
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Precision Edge®
SY58034U
Micrel, Inc.
32-PIN QFN (QFN-32)
Package
EP- Exposed Pad
Die
CompSide Island
Heat Dissipation
Heat Dissipation
Heavy Copper Plane
Heavy Copper Plane
VEE
VEE
PCB Thermal Consideration for 32-Pin QFN Package
(Always solder, or equivalent, the exposed pad to the PCB)
Package Notes:
1. Package meets Level 2 qualification.
2. All parts are dry-packaged before shipment.
3. Exposed pads must be soldered to a ground for proper thermal management.
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 474-1000
WEB
http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
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